This invention relates to direct injection (DI) of fuel into the combustion chambers of an internal combustion engine and, more particularly, to an integrated fuel delivery module for mounting a plurality of DI injectors and potentially other components on a direct injection gasoline or similar engine.
The direct injection (DI) of fuel, such as gasoline, into an engine combustion chamber requires that a DI fuel injector for each cylinder of the engine be mounted in the engine cylinder head or other combustion chamber defining member. The tip or nozzle end of the injector is directly exposed to high combustion pressures periodically occurring in the combustion chamber, and so a positive load must be applied to the injector to hold it in place and ensure that it remains sealed against leakage of exhaust gases from the combustion chamber.
In the past, this has been accomplished by fastening a tab or clamp on the injector directly to the cylinder head or other component. However, this requires that each injector be individually mounted to the cylinder head and adds to the manual labor cost in assembly of the engine.
The present invention solves this problem by providing an integrated fuel delivery module in which all the injectors intended for mounting in one bank of a multi-cylinder engine are installed prior to assembly. Fastening means are provided for mounting the module directly to the engine cylinder head or other combustion chamber defining component. The module includes fuel passages and may include related controls and features involved in fuel delivery to the engine. Loading springs are provided to apply a load between the inlet ends of the injectors and abutments in the body of the module so that the injectors are properly seated against their respective sealing surfaces with an adequate but not excessive load.
If desired, the module may comprise a portion of an intake manifold including air intake passages, exhaust gas recirculation passages and coolant passages with suitable controls for regulating EGR flow, as well as the fuel pressure delivered to the injectors.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.